Printing blanket bar assembly with edging strip locking means

ABSTRACT

A device for simplifying the installation of printing blankets in presses consisting of a bar which is mounted on the press and a strip which is permanently secured to the blanket. The bar has an open channel which is specially shaped to permit the easy insertion of the strip and has spring-loaded members to provide pressure on the strip for locking it in place. The bar is further provided with a separate locking device for holding the strip in place.

United States Patent 1191 Smith 1 Oct. 29, 1974 [54] PRINTING BLANKET BAR ASSEMBLY 2,236,230 3/1941 Worthington 101 4151 x WITH EDGING STRIP LOCKING MEANS 2,694,976 11/1954 Huck .1 101/4151 2,823,608 2/1958 Vandercook et a1. 101/390 Inventor: Kenneth Smlth, westhoughton, 3,017,830 1/1962 Penner 101/4151 England 3,288,062 11/1966 Westra 1 101/390 3,296,673 1/1967 Kirk atrick.., [OI/415.1 X [73] Asslgnee: Corporal, Dayton, 3,489,085 1/1970 Kirkgatrick... 101 4151 22 Filed; Sept. 11 1973 3,675,573 7/1972 Hanks 101/415.1

[21] Appl' 396157 Primary Examiner-R0bert E. Pulfrey Related US. Application Data Assistant Examiner-R. E. Suter [63] Continuation-impart of Ser. No. 194,216, Nov. 1,

1971, abandoned. [57] ABSTRACT 22 Cell. ..B 2111 25/56: gi f 2 iggg ggi ggi g g g izgg g h d d 378 127 I mounted on the press and a strip which is permanently le 0 earc 1 secured to the blanket. The bar has an open channel which is specially shaped to permit the easy insertion of the strip and has spring-loaded members to provide [56] References cued pressure on the strip for locking it in place. The bar is UNITED STATES PATENTS further provided with a separate locking device for 1,578,736 3/1926 John 101/4151 holding the strip in place. 1,686,065 10 1928 Blaine 101 4151 2,180,732 11 1939 Durham 101/4151 ux 2 ClalmS, 5 Drawing Figure-S PRINTING BLANKET BAR ASSEMBLY WITH EDGING STRIP LOCKING MEANS This application is a continuation-in-part of my application Ser. No. 194,2l6, filed Nov. l, l97l, now abandoned.

BACKGROUND OF THE INVENTION This invention relates to an assembly for mounting and holding a printing blanket in a printing press cylinder, particularly those known as sheet-fed presses. More specifically, the invention relates to a member which is mounted on the press in more or less permanent fashion and is used to retain the edge of the blanket, this edge having a special strip secured thereto which may be locked into place within the bar.

Sheet-fed printing presses are widely used in lithographic printing. In these presses, printing blankets are utilized to pick up the inked image from the printing plate and then transfer this image onto the paper which is to be printed. These printing blankets are essentially fabric sheets having a rubber face, and are wrapped around a cylinder which continually rotates to place the blanket in contact with the printing plate and the paper. One portion of the circumference of the cylinder is provided with an opening into which both ends of the blanket are inserted and held, one end of the blanket being fixed and the other attached to a cylindrical member, called a reel, which is rotated to provide proper tension of the blanket.

A number of considerations must be kept in mind when mounting these blankets on the cylinder, the foremost of which is to make sure that a proper tension is maintained on the blanket and that this tension is equal across the entire face of the blanket in order to provide even contact with the copy. Another factor is the simplicity of installation of the blanket and its subsequent removal, which must eventually take place when the blanket has become worn and needs replacmg.

The conventional method of securing the blanket to the cylinder consists of placing each end of the blanket between two bars and fastening them by means of a number of screws or bolts which must be spaced rather closely in order to provide even tension. Some attempts have been made to utilize special clamping devices such as described in US. Pat. No. 3,296,673, but the vast majority of presses in use still utilize the arrangement set forth above.

SUMMARY OF THE INVENTION The present invention constitutes an improvement over the prior art as described above, and also an improvement over US. Pat. application Ser. No. 762,855, filed Sept. 26, 1968, of common assignment (now abandoned). In accordance with the present invention a bar is mounted on a cylinder and used as a means for retaining the blanket in place, in a manner similar to that described in the above copending application. An edging strip is permanently affixed to each edge of the blanket and inserted into a channel formed in the bar. A number of spring-loaded biasing members are mounted in the bar to automatically hold the strip in place in the channel. In addition, a number of locking members, consisting of eccentrically mounted cylinders, are also mounted on the bar and are rotated to lock the strip in place in the bar. When it is desired to remove the strip, the cylinders are rotated in the opposite direction to release the strip which is then removed by pulling it out of the channel.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view of a portion of the printing cylinder and blanket illustrating the various components used for mounting.

FIG. 2 is an enlarged sectional view illustrating the holding bar, the edge of the blanket, the strip, and the mechanism, with the blanket locked in place.

FIG. 3 is a view similar to FIG. 2 illustrating the blanket being removed from or inserted into the bar.

FIG. 4 is a partial isometric view of the blanket, bar, and mechanism in installed position.

FIG. 5 is a view in partial section illustrating a springloaded biasing member.

DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 illustrates a typical printing press cylinder having an opening generally designated by the reference numeral 11. At one end of the opening is a portion 12 which is referred to in the trade as a lead, and on the opposite side of the opening is a reel 13 which is designed to be rotated in the direction illustrated by the arrow for the purpose of tightening the blanket and providing tension therein. This reel is shown in the tightened position so that the blanket is mounted and ready for operation. The lead portion 12 includes a shoulder 14 against which is mounted a blanket bar 15 which extends longitudinally of the cylinder. The reel 13 has a flat section in which is mounted a similar blanket bar 16.

For purposes of the present description, only the blanket bar 15 and its associated members will be described and discussed below, although it is understood that similar mechanisms may be utilized for the blanket bar 16 and its associated members.

FIG. 2-4 illustrate in further detail the novel blanket bar 15 having an upper wall 21 adjacent the shoulder 14, and a first side wall 20 connected to wall 21 and adjacent the wall 36 of the opening. The lowermost portion 23 of the bar is provided with a series of holes through which bolts 18 are used to mount the bar on the wall 36. A second side wall 24 is parallel to and shorter than the wall 20, and is not connected to the upper wall 21. A lower wall 25 is parallel to the wall 21 and interconnects the side walls 20 and 24. The walls all define a channel generally designated by reference numeral 37, having an opening between the upper wall 21 and the shorter side wall 24. The upper wall 21 has a beveled edge designated by reference numeral 22.

Mounted in the lower wall 25 is a series of biasing members which are illustrated in further detail in FIG. 5. These members are adapted to be threaded into the lower wall by means of the external threaded surface 31. Each of the members has a piston 32 mounted therein, and biased upwardly as shown by means of a spring 33. The pistons terminate in a locking member 34 which retains them within the housing of the members. The members may be adjustably mounted within the lower wall 25 by screwing them in or out, utilizing the slot 35.

Mounted on the shorter side wall 24 is a series of eccentrically mounted locking cylinders 26 which are mounted on a shaft 28. The cylinders are knurled to provide improved contact. Secured to the end of each cylinder is a gripping bar 27 to enable the cylinder to be easily rotated.

The printing blanket 17 has an edging strip 29 secured thereto which interengages and locks the end of the blanket as shown. The strip extends throughout the length of the blanket and completely envelopes the end of the blanket. The strip thus consists of side edges 38 and 39, a bottom edge 40, and a beveled upper edge 41 which conforms with the beveled surface 22 of the top wall 21.

The relationship between the edging strip and the channel, as seen in the drawings, is such that insertion and removal of the strip is simple. As can be seen, the top to bottom dimension (edge 41 to edge 40) of the strip is less than the channel spacing between the upper bar wall 21 and lower wall 25', and the lateral dimension (edge 38 to edge 39) of the strip is less than the channel spacing between the side bar walls and 24. The pressure of the pistons against the lower edge of the strip, combined with the contact of the cylinders 26 against the side wall 38 of the strip, eventually serve to lock the strip in the channel, as described in further detail below.

OPERATION OF THE ASSEMBLY When the blanket is to be installed on the printing press cylinder 10, the eccentric cylinders 26 are first rotated so that they are out of engagement with the edge 38 of the edging strip, as shown in FIG. 3, to permit the end of the blanket and edging strip to be inserted into the channel 37. Pressure of the bottom edge 40 of the edging strip against the piston 32 will cause it to retract against the spring to provide a maximum vertical opening for the edging strip. At the same time the strip is inserted at a slight angle as shown so that the top edge 41 of the edging strip clears the beveled edge 22 of the top wall 21 of the bar. The edge 39 of the edging strip will then be adjacent the side wall 36 of the opening and the beveled top edge 41 of the edging strip is locked against the beveled edge 22 of the bar. This releases pressure against the spring so that the edging strip is seated within the channel as shown in FIG. 2, with the bias force of the spring causing the pistons 32 to contact bottom edge 40 of the strip and keep it in the seated position.

As a next step, the cylinders 26 are rotated into the locking position shown in FIGS. 2 and 4 so that these cylinders contact the around side wall 38 of the edging strip and lock this strip in place. The printing blanket is then wrapped aroung the rest of the printing press cylinder in a conventional manner (not shown) and the other end is then inserted into the blanket bar 16 on the reel. It should be noted that although the blanket bar 16 is illustrated as having eccentric cylinders, these cylinders may be omitted on the reel because they are not always required in certain types of installations. However, it is contemplated that the biasing members 30 will be provided in the blanket bar on the reel and will operate in the same manner as those described previously.

By means of the novel assembly, both ends of the printing blanket are positively locked within the channel, and are evenly supported along the length of the blanket ends so that proper operation of the blanket in a printingsystem may result.

When it is desired to remove the cylinder, the eccentric cylinders are again rotated to the FIG. 3 position, so that these cylinders are out of contact with the strip. Tilting the strip at a slight angle as shown in FIG. 3 will then simplify removal thereof.

The form of the invention described above is exemplary, but other variations are contemplated within the scope of the invention.

I claim:

1. In a printing press cylinder having an opening therein, an assembly for mounting a printing blanket within said opening, said blanket having an edging strip secured to one end thereof; said assembly including a bar mounted within said opening and extending longitudinally of said cylinder, said bar comprising a first side wall adjacent one wall of said opening, a second side wall parallel to said first side wall, a lower wall interconnecting said side walls, and an upper wall parallel to said lower wall and connected to said first side wall, said walls all defining a channel for receiving said edging strip; said second side wall having locking members mounted thereon comprising eccentrically mounted cylinders which may be rotated out of contact with said edging strip during insertion or removal thereof, said lower wall having a plurality of biasing members biased toward said upper wall; said edging strip having a lesser top to bottom dimension than the channel spacing between said upper and lower walls and a lesser transverse dimension than the channel spacing between said side walls, said edging strip contacting said first side wall and said top wall upon insertion into said channel but spaced from said second side wall and said bottom wall; said locking members operable to contact one lateral edge of said edging strip and said biasing members contacting the lower surface of said edging strip, after insertion into said channel.

2. The assembly of claim I in which said biasing means comprises a plurality of spring-loaded pistons.

l l l =l 

1. In a printing press cylinder having an opening therein, an assembly for mounting a printing blanket within said opening, said blanket having an edging strip secured to one end thereof; said assembly including a bar mounted within said opening and extending longitudinally of said cylinder, said bar comprising a first side wall adjacent one wall of said opening, a second side wall parallel to said first side wall, a lower wall interconnecting said side walls, and an upper wall parallel to said lower wall and connected to said first side wall, said walls alL defining a channel for receiving said edging strip; said second side wall having locking members mounted thereon comprising eccentrically mounted cylinders which may be rotated out of contact with said edging strip during insertion or removal thereof, said lower wall having a plurality of biasing members biased toward said upper wall; said edging strip having a lesser top to bottom dimension than the channel spacing between said upper and lower walls and a lesser transverse dimension than the channel spacing between said side walls, said edging strip contacting said first side wall and said top wall upon insertion into said channel but spaced from said second side wall and said bottom wall; said locking members operable to contact one lateral edge of said edging strip and said biasing members contacting the lower surface of said edging strip, after insertion into said channel.
 2. The assembly of claim 1 in which said biasing means comprises a plurality of spring-loaded pistons. 